/*
 * Copyright © 2017-2023 TemplateFactory(xiaoymin@foxmail.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


package com.github.xiaoymin.template.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

/**
 * This class holds methods useful for constructing custom classloaders.
 * 
 * @author Jeff Butler
 * 
 */
public class ClassloaderUtility {
    
    private static final Logger LOG = LoggerFactory.getLogger(ClassloaderUtility.class);
    /**
     * Utility Class - No Instances.
     */
    private ClassloaderUtility() {
    }
    
    public static ClassLoader getCustomClassloader(Collection<String> entries) {
        List<URL> urls = new ArrayList<>();
        File file;
        
        if (entries != null) {
            for (String classPathEntry : entries) {
                file = new File(classPathEntry);
                if (!file.exists()) {
                    LOG.warn("classPath File not Exists,file Path:{}", classPathEntry);
                    continue;
                }
                
                try {
                    urls.add(file.toURI().toURL());
                } catch (MalformedURLException e) {
                    // this shouldn't happen, but just in case...
                    throw new RuntimeException("has Exception,message:" + e.getMessage() + ",classpath:" + classPathEntry);
                }
            }
        }
        
        ClassLoader parent = Thread.currentThread().getContextClassLoader();
        
        return new URLClassLoader(urls.toArray(new URL[urls
                .size()]), parent);
    }
}
